# Thread: partial diff. rate of change!

1. ## partial diff. rate of change!

the area of a parallelogram with adjacent sides a and b and including $angle \theta$ is given by $A=absin\theta$. find the rate of change of A with respect to a when a=10, b=20 and $\theta=\frac{\pi}{6}$

pls guys take a look at the problem above, it appears it lacks sufficient information because the values for the rate of change were not given. prove me right if i am wrong, thanks

2. ## Re: partial diff. rate of change!

Originally Posted by lawochekel
the area of a parallelogram with adjacent sides a and b and including $angle \theta$ is given by $A=absin\theta$. find the rate of change of A with respect to a when a=10, b=20 and $\theta=\frac{\pi}{6}$

pls guys take a look at the problem above, it appears it lacks sufficient information because the values for the rate of change were not given. prove me right if i am wrong, thanks
You are expected to evaluate \displaystyle \begin{align*} \frac{\partial A}{\partial a} \end{align*} at the values given.

3. ## Re: partial diff. rate of change!

"prove me right if I am wrong". Now there's a challenge!

You do not need "values for the rate of change" because you are not asked for the "rate of change" of A, you are asked for the "rate of change with respect to a" which is the partial derivative as Prove It indicated.